1. Field of the Invention
The present invention relates to battery packs which are constructed with rechargeable batteries such as Li-ion batteries.
2. Description of the Related Art
An electric device is primarily powered by an AC voltage supplied from a commercial power source, or a DC voltage supplied from battery cells. The above-described electric devices using battery cells as a power source include a type of an electric device, as represented by such as a cellular telephone, which specially fits very small load current applications, and uses a battery pack oriented toward reduction in size and weight, and another type of an electric device, as represented by such as a power tool, which meets the requirements of a large load current, and uses a battery pack oriented toward large current discharging.
An example of such a conventional battery pack is disclosed in Japanese Patent Application Publication No. 2002-254355.